Cord-guiding mechanism for buttonhole-sewing machines



Feb. 4, 1930. V 'E. B. ALLEN 1,745,832

CORD GUIDING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed Jan. 17, 1928 i a a J E f T\ 1 16 12% Q 5 i410 Q INVENTOR 4 wlm ss gs.

A y a buttonhole.

nism includes a reciprocating needle sup- Patented Feb. 4, 1934) um STATES PATENT QFFICE EDWARD B. ALLEN, OF NEWTOVJN, CONNECTICUT, ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY CORD-GUIDING- MECHANISM FOR BUTTONHOLE-SEWING MACHINES Application filed January 17,1928. Serial No. 247,284.

This invention relates to buttonhole sewing machines, more particularly of the type having stitch-forming mechanism which turns about an axis normal to the plane of the work in sewing around the eyelet-end of Such stitch-forming mechaported and operated above the work, and under-thread mechanism mounted on a rotary turret which carries the usual needlethroat member customarily formed with a guiding aperture for leading a cord within the range of action of the stitch-forming devices,iso that the cord will beembraced within the overseam.

Due to the fact that the turret is turned about its axis in sewing around the end of the buttonhole and is reversely turned after the buttonhole is completed, to restore the stitch-forming mechanism to initial position, there has been difficulty in freely guiding the cord from the supply to the needle-throat member; the cord being heretofore subjected to a variable drag and to a take-up and slackgiving action due to the changing relation of the needle-throat member to the cord leading to said member.

An object of the present invention is to provide a cord-guiding mechanism which maintains a fixed relation between the needlethroat member and other cord-guiding elements, so that rotation of the turret will have no effect upon the feed of the cord from the source of supply to the needle-throat member, thus eliminating a variable condition which heretofore tended to produce variations in the resultant overseam at diflerent positions around the buttonhole.

The invention comprises the provision of a lead-in or introductory cord-guide which is disposed in theaxis of rotation of the turret, followed by additional cord-guiding means carried by the turret. The guiding means preferably leads the cord upwardly along-side the turret, out of range of the turret-mechanism, and inwardly to the cordguiding aperture in the needle-throat memher. When the turret turns in sewing around the end of a buttonhole, the guiding devices sweepvaround with the turret and maintain at all times a fixed distance from the latter and from the guide-tube, thus avoiding any take-up or slack-giving action upon the cord and introducing no variable friction or drag upon the cord. The introductory guide is I preferably in the form of a tube mounted as a bushing in a hole in the table which sup ports the machine; the cord supply-spool being disposed below the table.

In the accompanying drawings, Fig. 1 is a front end elevation of the bed of a buttonhole sewing machine embodying the invention. Fig. 2 is a plan view of the turret and cord-guide, and Fig. 8 is a section on the line 33, Fig. 1.

The invention is shown as embodied in a buttonhole sewing machine, such as disclosed inthe patent to Allen, et al., No. 1,372,478, of- March 22, 1921. prises a reciprocating and laterally vibrating needle 1 and a bed 2 within which is mounted for turning movements about a vertical axis, the turret 3 carrying the usual under-thread mechanism and needle-throat member 4 having the cord-guiding aperture 5 through which the cord is led to a position within range of the vibrating needle 1. The under-thread mechanism includes the thread- Such a machine com-.

ed and non-threaded loopers 3 and 3*, respectively, operating in an arcuate path about the pivot screw 3. 7

According to the present improvement there is fixed to the turret by the screw 6 an outwardly extending arm 7 to which is fixed by screws 8 the angular guide-arm 9 having a vertical portion 10 and an inwardly and upwardly inclined portion 11 extending above the path of the loopers 3 and 3 and termihating near the cord-guiding aperture 5 in The guide 15 comprises a roller-stud 18 journaled on a pin 19 set in the arm 10. The stud 18 is covered by a sheet-metal guard 20 having at one end an inturned lip 21 in engagement with the arm 10. The guard 20 is secured to the arm 10 by the screw 22 and retains the cord in engagement with the roller-stud 18. The guide 16 is similar in construction'to the guide 15. The guide 17 comprises a shank'secured by screws 23 to the arm 11; such shank being bent at its upper free endinto the form of a guide-eye 24 through which the cord 12 passes to the needle-throat member.

In the operation of the machine, the cordguide sweeps around the turrets axis as indicated by the dotted semi-circle in Fig. 2, maintaining a fixed relation to the turret and needle-throat member. Also, the guide 15 is maintained at a fixed distance from the tube 14, so that there is no take-up or slackgiving action on the cord at any time, and

the cord is maintained at all times entirely out of range ofthe under-thread mechanism.

Having thus set forth the nature of the invention, what I claim herein is 1. In a buttonhole sewing machine, the combination with stitch-forming mechanism including an upper needle, under-thread mechanism, a rotary turret carrying said EDWARD B. ALLEN.

under-thread mechanism, and a needle-throat member, of a cord-guide disposed below and coaxial with the turret, and cord-guiding means carried by and spaced from'said turret and adapted to lead'the cord from said first mentioned cord-guide upwardly alongside and externally of the turret and inwardly to said needle-throat member, said cord-guiding means maintaining the cord out of range of the under-thread mechanism.

.2. In a buttonhole sewing machine, the combination with stitch-forming mechanism including an upper needle, under-thread mechanism, a rotary turret carrying said under-thread mechanism, and a needlethroat member having a cord-guiding aperture, of a cord-guide disposed below and coaxial with the turret, and cord-guiding means carried by said turret and including an arm spaced from and secured to said turret and having a downwardly extending portion and an inwardly and upwardly extending, portion terminating adjacent the needlethroatmember, and cord-guiding means adjacent the free-ends of said portions.

3. In a buttonhole sewing machine, the combination with an upper needle, underthread mechanism including threaded and non-threaded loopers, a needle-throat memher, and a rotary turret carrying said underthre'ad mechanism and needle-throat member, of a cord-guide disposed below and coaxial with the. turret, and means carried by the turret for leading the cord from said cordguide to said needle-throat. member exter- 

